rice.pastry.wire
Class WireNodeHandle

java.lang.Object
  java.util.Observable
      rice.p2p.commonapi.NodeHandle
          rice.pastry.NodeHandle
              rice.pastry.dist.DistNodeHandle
                  rice.pastry.dist.DistCoalesedNodeHandle
                      rice.pastry.wire.WireNodeHandle

All Implemented Interfaces:

LocalNodeI, MessageReceiver, java.util.Observer, SelectionKeyHandler, java.io.Serializable

public class WireNodeHandle

extends DistCoalesedNodeHandle

implements SelectionKeyHandler

Class which represents a node handle in the socket-based pastry protocol. Initially, all of the messages are sent over UDP. If a message is too large to be sent over the UDP protocol (as determined by the MAX_UDP_MESSAGE_SIZE), then a socket connection is opened to the remote node.

See Also:

Serialized Form

Field Summary

static int	MAX_UDP_MESSAGE_SIZE the largest message size to send over UDP
static int	PING_THROTTLE the throttle (pings only sent this many seconds)
static int	SOCKET_BUFFER_SIZE the size of the "receive" buffer for the socket
static int	STATE_USING_TCP using TCP
static int	STATE_USING_UDP using UDP
static int	STATE_USING_UDP_WAITING_FOR_TCP_DISCONNECT waiting to disconnect from TCP from remote side
static int	STATE_USING_UDP_WAITING_TO_DISCONNECT waiting to disconnect

Fields inherited from class rice.pastry.dist.DistCoalesedNodeHandle

alive, DEFAULT_DISTANCE, isInPool, isLocal

Fields inherited from class rice.pastry.dist.DistNodeHandle

address, nodeId

Fields inherited from class rice.pastry.NodeHandle

localnode

Fields inherited from class rice.p2p.commonapi.NodeHandle

DECLARED_DEAD, DECLARED_LIVE, PROXIMITY_CHANGED

Fields inherited from interface rice.pastry.LocalNodeI

pending

Constructor Summary

WireNodeHandle(java.net.InetSocketAddress address, NodeId nid)
Constructor.

WireNodeHandle(java.net.InetSocketAddress address, NodeId nid, PastryNode pn)
Alternate constructor with local Pastry node.

Method Summary

void	accept(java.nio.channels.SelectionKey key) Requeired by the SelectionKeyHandler interface.
void	connect(java.nio.channels.SelectionKey key) Called by the socket manager whnever this node handle needs to complete it's connection to it's remote node.
void	connectToRemoteNode(java.util.Iterator messages) Method which initiates a connection to a remote node.
void	disconnect() Method that is designed to be called by the SocketManager when it wishes for this node handle to disconnect.
int	getState() Returns the state of this WireNodeHandle
boolean	isWriteEnabled() Gets the WriteEnabled attribute of the WireNodeHandle object
void	notifyKilled() prints Potentially lost the message for all messages in queue
void	notifyPotentiallyLostMessage(java.util.Iterator i) prints Potentially lost the message for all messages in the iterator
boolean	pingImpl() Ping the remote node now, and update the proximity metric.
void	pingResponse() Method which is called by the SocketPingManager when a ping response comes back for this node.
void	pingStarted() Method which is called by the PingMessage right before it is going to be sent across the wire.
void	read(java.nio.channels.SelectionKey key) Called by the socket manager whenever there is data to be read from this node handle's remote node.
void	receiveMessageImpl(Message msg) Called to send a message to the node corresponding to this handle.
void	receiveSocketMessage(SocketCommandMessage message) Method which is called when a SocketCommandMessage comes across an open socket for this node handle.
void	setKey(java.nio.channels.SelectionKey key, SocketCommandMessage scm) Method which sets the SelectionKey of this node handle.
java.lang.String	toStringImpl() implementation for toString()
void	write(java.nio.channels.SelectionKey key) Method which is called when the key becomes writable.

Methods inherited from class rice.pastry.dist.DistCoalesedNodeHandle

addObserver, afterSetLocalNode, clearChanged, countObservers, debug, deleteObserver, deleteObservers, equals, getIsInPool, hasChanged, hashCode, isAlive, markAlive, markDead, notifyObservers, notifyObservers, ping, proximity, receiveMessage, setChanged, setIsInPool, setProximity, toString, update

Methods inherited from class rice.pastry.dist.DistNodeHandle

getAddress, getNodeId

Methods inherited from class rice.pastry.NodeHandle

assertLocalNode, getId, getLocalNode, setLocalNode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

STATE_USING_UDP

public static final int STATE_USING_UDP

using UDP

See Also:

Constant Field Values

STATE_USING_TCP

public static final int STATE_USING_TCP

using TCP

See Also:

Constant Field Values

STATE_USING_UDP_WAITING_FOR_TCP_DISCONNECT

public static final int STATE_USING_UDP_WAITING_FOR_TCP_DISCONNECT

waiting to disconnect from TCP from remote side

See Also:

Constant Field Values

STATE_USING_UDP_WAITING_TO_DISCONNECT

public static final int STATE_USING_UDP_WAITING_TO_DISCONNECT

waiting to disconnect

See Also:

Constant Field Values

MAX_UDP_MESSAGE_SIZE

public static int MAX_UDP_MESSAGE_SIZE

the largest message size to send over UDP

SOCKET_BUFFER_SIZE

public static int SOCKET_BUFFER_SIZE

the size of the "receive" buffer for the socket

PING_THROTTLE

public static int PING_THROTTLE

the throttle (pings only sent this many seconds)

Constructor Detail

WireNodeHandle

public WireNodeHandle(java.net.InetSocketAddress address,
                      NodeId nid)

Constructor.

Parameters:

address - The address of the host on which this node resides

nid - The NodeId of this host

WireNodeHandle

public WireNodeHandle(java.net.InetSocketAddress address,
                      NodeId nid,
                      PastryNode pn)

Alternate constructor with local Pastry node.

Parameters:

address - The address of the host on which this node resides

nid - The NodeId of this host

pn - The local Pastry node

Method Detail

getState

public int getState()

Returns the state of this WireNodeHandle

Returns:

The state of this handle

isWriteEnabled

public boolean isWriteEnabled()

Gets the WriteEnabled attribute of the WireNodeHandle object

Returns:

The WriteEnabled value

setKey

public void setKey(java.nio.channels.SelectionKey key,
                   SocketCommandMessage scm)

Method which sets the SelectionKey of this node handle. Is designed to be called whenever a TCP connection has been established. All pending message will now be sent over TCP using the socket attached to this SelectionKey. If a socket has already been established, there is a protocol for determining which socket to close. If the address:port of the local is less than that of the remote, this node ignores the incoming key. Otherwise, it will kill it's own socket and use the new key as the "real" socket. NOTE: There are known problems with this implementation, especially under high stress.

Parameters:

key - The new SelectionKey

scm - The new Key value

receiveSocketMessage

public void receiveSocketMessage(SocketCommandMessage message)

Method which is called when a SocketCommandMessage comes across an open socket for this node handle.

Parameters:

message - The message coming across the wire.

notifyKilled

public void notifyKilled()

prints Potentially lost the message for all messages in queue

receiveMessageImpl

public void receiveMessageImpl(Message msg)

Called to send a message to the node corresponding to this handle.

Specified by:

receiveMessageImpl in class DistCoalesedNodeHandle

Parameters:

msg - Message to be delivered, may or may not be routeMessage.

notifyPotentiallyLostMessage

public void notifyPotentiallyLostMessage(java.util.Iterator i)

prints Potentially lost the message for all messages in the iterator

Parameters:

i - an iterator of messages to print out the error message for

connectToRemoteNode

public void connectToRemoteNode(java.util.Iterator messages)

Method which initiates a connection to a remote node. This is done by connecting to the server socket on the remote node. This can be called by the receiveMessageImpl, if there is a too-big message waiting to be sent, or by the TransmissionManager if there are too many messages in the queue.

Parameters:

messages - the initial queue

disconnect

public void disconnect()

Method that is designed to be called by the SocketManager when it wishes for this node handle to disconnect. Once this is called, the node handle will finish writing out any pending objects in the queue, and then send a DisconnectMessage to the remote node. Upon receiving this DisconnectMessage, the remote node will finish writing out any pending objects, and then will actually disconnect the socket.

accept

public void accept(java.nio.channels.SelectionKey key)

Requeired by the SelectionKeyHandler interface. Should never be called (because we never accept connections).

Specified by:

accept in interface SelectionKeyHandler

Parameters:

key - DESCRIBE THE PARAMETER

connect

public void connect(java.nio.channels.SelectionKey key)

Called by the socket manager whnever this node handle needs to complete it's connection to it's remote node. Is specified by the SelectionKeyHandler interface.

Specified by:

connect in interface SelectionKeyHandler

Parameters:

key - DESCRIBE THE PARAMETER

write

public void write(java.nio.channels.SelectionKey key)

Description copied from interface: SelectionKeyHandler

Method which is called when the key becomes writable.

Specified by:

write in interface SelectionKeyHandler

Parameters:

key - The key which is writable.

read

public void read(java.nio.channels.SelectionKey key)

Called by the socket manager whenever there is data to be read from this node handle's remote node. Is specified from the SelectionKeyHandler interface.

Specified by:

read in interface SelectionKeyHandler

Parameters:

key - DESCRIBE THE PARAMETER

pingImpl

public boolean pingImpl()

Ping the remote node now, and update the proximity metric. This method ALWAYS uses UDP, even if there already is a TCP socket open.

Specified by:

pingImpl in class DistCoalesedNodeHandle

Returns:

liveness of remote node.

pingStarted

public void pingStarted()

Method which is called by the PingMessage right before it is going to be sent across the wire. Marks the beginning of a ping as now.

pingResponse

public void pingResponse()

Method which is called by the SocketPingManager when a ping response comes back for this node.

toStringImpl

public java.lang.String toStringImpl()

implementation for toString()

Specified by:

toStringImpl in class DistCoalesedNodeHandle

Returns:

A String representation of the node handle.